Engine hesitation & reduced mph after emission upgrade

[Standup Rider]

Hello, I am new here so sorry about asking this question that’s probably already been asked 100 times.
my question is how can I get the 3 to 4 mph I lost and also get rid of the very noticeable engine acceleration delay at first when the engine is cool but was not there before my 2016 Ram eco diesel had this required emissions upgrade that was performed at the dealership free of charge.

 

[autoX]

I've got the same sort of thing. Engine cold, set off and plomp, it dies and recovers within a second, battery light comes on that's how low the revs go. This is after my used engine installation. full delete and tune.

I think it's actually a transmission issue, tho. I am going to try selecting 1 and see what happens.